nginx负载均衡

1： 我们把项目部署在两台服务器上，在hosts文件里面配置域名解析

2： 配置nginx服务器的负载均衡

#user  nobody;
worker_processes  1;
#error_log  logs/error.log;
#error_log  logs/error.log  notice;
#error_log  logs/error.log  info;
#pid        logs/nginx.pid;

events {
    worker_connections  1024;
}

http {
    include       mime.types;
    default_type  application/octet-stream;

    #log_format  main  '$remote_addr - $remote_user [$time_local] "$request" '
    #                  '$status $body_bytes_sent "$http_referer" '
    #                  '"$http_user_agent" "$http_x_forwarded_for"';

    #access_log  logs/access.log  main;

    sendfile        on;
    #tcp_nopush     on;

    #keepalive_timeout  0;
    keepalive_timeout  65;

    #gzip  on;

    server {
        listen       80;
        server_name  localhost;

        #charset koi8-r;

        #access_log  logs/host.access.log  main;

        location / {
            root   html;
            index  index.html index.htm;
        }

        error_page   500 502 503 504  /50x.html;
        location = /50x.html {
            root   html;
        }

    }
    #======================      我们这里自定义负载均衡      =====================
    server {  
        # 监听80端口
        listen       80;
        server_name  www.wulei.com;
        
        location / {
            # 用来获取nginx的真实ip
            proxy_set_header X-Real_IP $remote_addr;
        
            proxy_pass  http://myservers;
        }
    }
    upstream myservers{
        # ip_hash负载均衡策略：  
        ip_hash;
        # 服务器地址
        
        server 192.168.5.6:8081;
        server 192.168.5.5:8081;
    }
}

测试： 

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nginx负载均衡策略：

1.  ip_hash 策略：每个请求按访问ip的hash结果分配，这样每个访客固定访问一个后端服务器，可以解决session的问题。

2.  默认轮询策略：

upstream myservers{
    server 192.168.5.6:8081;
    server 192.168.5.5:8081;
}

3.  权重策略：指定轮询几率，weight和访问比率成正比

upstream myservers{
    server 192.168.5.6:8081 weight=9;
    server 192.168.5.5:8081weight=2;
}

4.  fiar策略(第三方)：按后端服务器的响应时间来分配请求，响应时间短的优先分配。

upstream myservers{
    server 192.168.5.6:8081;
    server 192.168.5.5:8081;
    fair; 
}